If patterns of human love subtlely change, all sorts of social and political atrocities can escalate

Serotonin-enhancing antidepressants (such as Prozac and many others) can jeopardize feelings of romantic love, feelings of attachment to a spouse or partner, one's fertility and one's genetic future.

I am working with psychiatrist Andy Thomson on this topic. We base our hypothesis on patient reports, fMRI studies, and other data on the brain.

Foremost, as SSRIs elevate serotonin they also suppress dopaminergic pathways in the brain. And because romantic love is associated with elevated activity in dopaminergic pathways, it follows that SSRIs can jeopardize feelings of intense romantic love. SSRIs also curb obsessive thinking and blunt the emotions--central characteristics of romantic love. One patient described this reaction well, writing: "After two bouts of depression in 10 years, my therapist recommended I stay on serotonin-enhancing antidepressants indefinitely. As appreciative as I was to have regained my health, I found that my usual enthusiasm for life was replaced with blandness. My romantic feelings for my wife declined drastically. With the approval of my therapist, I gradually discontinued my medication. My enthusiasm returned and our romance is now as strong as ever. I am prepared to deal with another bout of depression if need be, but in my case the long-term side effects of antidepressants render them off limits".

SSRIs also suppress sexual desire, sexual arousal and orgasm in as many as 73% of users. These sexual responses evolved to enhance courtship, mating and parenting. Orgasm produces a flood of oxytocin and vasopressin, chemicals associated with feelings of attachment and pairbonding behaviors. Orgasm is also a device by which women assess potential mates. Women do not reach orgasm with every coupling and the "fickle" female orgasm is now regarded as an adaptive mechanism by which women distinguish males who are willing to expend time and energy to satisfy them. The onset of female anorgasmia may jeopardize the stability of a long-term mateship as well.

Men who take serotonin-enhancing antidepressants also inhibit evolved mechanisms for mate selection, partnership formation and marital stability. The penis stimulates to give pleasure and advertise the male's psychological and physical fitness; it also deposits seminal fluid in the vaginal canal, fluid that contains dopamine, oxytocin, vasopressin, testosterone, estrogen and other chemicals that most likely influence a female partner's behavior.

I believe that Homo sapiens has evolved (at least) three primary, distinct yet overlapping neural systems for reproduction. The sex drive evolved to motivate ancestral men and women to seek sexual union with a range of partners; romantic love evolved to enable them to focus their courtship energy on a preferred mate, thereby conserving mating time and energy; attachment evolved to enable them to rear a child through infancy together. The complex and dynamic interactions between these three brain systems suggest that any medication that changes their chemical checks and balances is likely to alter an individual's courting, mating and parenting tactics, ultimately affecting their fertility and genetic future.

The reason this is a dangerous idea is that the huge drug industry is heavily invested in selling these drugs; millions of people currently take these medications worldwide; and as these drugs become generic, many more will soon imbibe — inhibiting their ability to fall in love and stay in love. And if patterns of human love subtlely change, all sorts of social and political atrocities can escalate.